A violent cosmic explosion has unleashed the brightest blast of X-rays ever detected from distant space, a signal so bright it temporary blinded the NASA space telescope assigned to spot it.

The powerful explosion, called a gamma-ray burst, was detected by NASA's Swift observatory, scientists announced Wednesday. Gamma-ray bursts are narrow beams of intense radiation shot out when stars explode in supernovas. In addition to gamma-ray light, they also produce X-rays and other forms of radiation, including visible light.

This recent event, dubbed GRB 100621A, was particularly powerful.

"This gamma-ray burst is by far the brightest light source ever seen in X-ray wavelengths at cosmological distances," said Penn State University astronomer David Burrows, lead scientist for Swift's X-ray Telescope. [Swift's gamma-ray burst photo]

Unprecedented brightness

The onslaught of light in X-ray wavelengths, which are shorter than visible light wavelengths, quickly overwhelmed the detector when it impacted June 21.

"The burst was so bright when it first erupted that our data-analysis software shut down," said Phil Evans, a postdoctoral research assistant at the University of Leicester in the United Kingdom who wrote parts of Swift's X-ray-analysis software. "So many photons were bombarding the detector each second that it just couldn't count them quickly enough. It was like trying to use a rain gauge and a bucket to measure the flow rate of a tsunami."

Light from this explosion traveled through space for 5 billion years before slamming into Swift, overwhelming its X-ray camera. The observatory, launched in November 2004, was designed specifically to hunt for gamma-ray bursts, though scientists didn't count on a blast quite so strong.

"The intensity of these X-rays was unexpected and unprecedented," said Neil Gehrels, Swift's principal investigator at NASA's Goddard Space Flight Center in Greenbelt, Md.

GRB 100621A was the brightest blast of X-ray light since Swift's X-ray telescope began observing in 2005.

"Just when we were beginning to think that we had seen everything that gamma-ray bursts could throw at us, this burst came along to challenge our assumptions about how powerful their X-ray emissions can be," Gehrels said.

One for the record books

After the shutdown, Swift quickly got back online, and scientists were able to recover the data the observatory acquired during the onslaught. The observations allowed astronomers to learn more about these mysterious explosions, including just how bright they can be.

Swift's measurements showed that the burst emitted 143,000 X-ray photons per second during its short period of greatest brightness. That's more than 140 times brighter than the brightest continuous X-ray source in the sky – a neutron star that releases a steady 10,000 X-ray photons per second.

"When I first saw the strange data from this burst, I knew that I had discovered something extraordinary," Evans said. "It was an indescribable feeling when I realized, at that moment, that I was the only person in the whole universe who knew that this extraordinary event had occurred. Now, after our analysis of the data, we know that this burst is one for the record books."

Gamma-ray bursts focus most of their energy in the short-wavelength, high-frequency range of X-rays and gamma-rays. In fact, they don't stand out at all in optical and ultraviolet wavelengths, emitting only a middling amount of light compared to other objects in the sky.

When a very massive star runs out of fuel and reaches the end of its life, it will collapse into an extremely dense black hole. This event releases an explosion of energy, including some that gets channeled into beams of gamma-ray and X-ray light

MUFON

Stabilize the camera on a tripod. If there is no tripod, then set it on top of a stable, flat surface. If that is not possible lean against a wall to stabilize your body and prevent the camera from filming in a shaky, unsteady manner.

Provide visual reference points for comparison. This includes the horizon, treetops, lampposts, houses, and geographical landmarks (i.e., Horsetooth Reservoir, Mt. Adams, etc.) Provide this in the video whenever is appropriate and doesn’t detract from what your focus is, the UFO.

Narrate your videotape. Provide details of the date, time, location, and direction (N,S,E,W) you are looking in. Provide your observations on the weather, including approximate temperature, windspeed, any visible cloud cover or noticeable weather anomalies or events. Narrate on the shape, size, color, movements, approximate altitude of the UFO, etc and what it appears to be doing. Also include any unusual physical, psychological or emotional sensations you might have. Narrate any visual reference points on camera so they correlate with what the viewer will see, and thereby will be better able to understand.

Be persistent and consistent. Return to the scene to videotape and record at this same location. If you have been successful once, the UFO sightings may be occurring in this region regularly, perhaps for specific reasons unknown, and you may be successful again. You may also wish to return to the same location at a different time of day (daylight hours) for better orientation and reference. Film just a minute or two under “normal” circumstances for comparison. Write down what you remember immediately after. As soon as you are done recording the experience/event, immediately write down your impressions, memories, thoughts, emotions, etc. so it is on the record in writing. If there were other witnesses, have them independently record their own impressions, thoughts, etc. Include in this exercise any drawings, sketches, or diagrams. Make sure you date and sign your documentation.

Always be prepared. Have a digital camera or better yet a video camera with you, charged and ready to go, at all times. Make sure you know how to use your camera (and your cell phone video/photo camera) quickly and properly. These events can occur suddenly, unexpectedly, and often quite randomly, so you will need to be prepared.